Robust power balancing scheme for the grid-forming microgrid

Control over the voltage and the frequency instabilities in a grid-forming microgrid due to the power mismatch conditions become the point of concern. Therefore, the study implements a self-tuned proportional-integral integrated active power-voltage drooping and reactive power-frequency boosting control strategy for the precise power sharing among the distributed generators. Furthermore, to handle the power deficit scenarios and protect the system from the blackout, a system independent and priority-based adaptive three-stage load shedding strategy is proposed. The sensitivity of the strategy depends on the system inertia and is computed according to the varying absolute rate-of-change-of-frequency. The strategy incorporates the operation of a hybrid storage system comprised of battery and supercapacitor present in the microgrid, to provide a reliable power supply to the customers for a considerable time rather than a sudden load shedding. The effectiveness of the proposed strategies is investigated on a modified IEEE 13-bus system. The study is simulated in the time domain, on the podium of MATLAB 2015b.